refactor: move note writes behind projection events

[h4yfans]

What

Move normal note and journal write paths fully onto domain-event/projector flows instead of draining projections inline.

Why

Phase 4 was marked complete, but local note and journal mutations still awaited projector execution and rename/repair compatibility paths could still mutate index state directly.

How

• removed inline flushProjectionEvents() waits from local note CRUD and journal IPC mutation handlers
• routed duplicate note-ID repair in notes.ts through deleteNoteFromCache and syncNoteToCache instead of direct cache/canonical writes
• changed rename-tracker to detect and emit rename events only, and replayed markdown renames through syncNoteToCache in the watcher
• switched watcher, journal sync apply, and CRDT writeback paths to queue projection draining with void flushProjectionEvents()
• added regression coverage to lock in the non-inline projection behavior
• left the indexer rebuild awaits unchanged because concurrent rebuild duplicate detection still depends on note_cache visibility

Type

• feat — new feature
• fix — bug fix
• refactor — restructure without behavior change
• style — visual/UI only
• perf — performance improvement
• test — adding or updating tests
• chore — tooling, deps, config
• docs — documentation only
• ci — CI/CD changes

Test plan

• Unit tests added/updated

• Integration tests added/updated

• Manual testing (describe below)

• pnpm exec vitest run --config config/vitest.config.ts --project main src/main/ipc/journal-handlers.test.ts src/main/vault/notes.test.ts src/main/vault/rename-tracker.test.ts src/main/vault/watcher.test.ts

• pnpm typecheck:desktop

Screenshots

N/A

Checklist

• Self-reviewed the diff
• No hardcoded secrets or credentials
• Files stay under ~500 LOC
• Follows immutable data patterns